add plain text option for mail #2029
bugfix to two failed tests
Remove pre tag attributes.
Patch #2005, nl.yml update
Patch #2001, update for Polish language
#1992 update pt.yml, thanks to Pedro Araújo
Patch #1987, ca.yml update, thanks to Joan Duran for file
#1988, update for ko.yml
Escape image filename regexp (#1971).
Added tests to cover IssueStatus.destroy and IssueStatus.check_integrity
